Sorry, the address was incorrect!
SO ...
today I have uploaded GRASS 4.2.1 binaries for Linux 2.x.
You find the package and the install instructions on
the page
http://www.laum.uni-hannover.de/iln/grass/grass42/
The final bugfixing for v.clean and v.build has been
done (a new src-package is also there and the diffs).
So I expect this version to be stable.
Have fun
Markus Neteler
PS.: If you have modules missing in the package you are welcome
to send it in (neteler@geog.uni-hannover.de).